The three-tier application architecture model is the correct choice because it separates the user interface, business logic, and data storage layers. This approach provides enhanced security as each tier can be secured independently, and it allows for better scalability and manageability of the application. The separation of concerns makes maintenance and updates more efficient as well. In contrast, the one-tier model is not ideal as it would have all parts of the application on a single platform, creating a single point of failure and security risk. The two-tier model would not provide as clear a separation between the business logic and data storage as the three-tier model. The n-tier model could be considered an alternative, but for this scenario, where a clear distinction is made between three key components, the three-tier model fits best.